Starting piece for spiral wire zip fasteners



A! zn-w July 19, 1960 H. POREPP 2,945,276

STARTING PIECE FOR SPI'RAL WIRE ZIP FASTENERS Filed Feb. 19, 1957 United States Patent (Y v 2,945,276 STARTING PIECE FOR SPIRAL WIRE ZIP FASTENERS Hans Porepp, Essen, Germany, assignor to Opti-Werk .m.b.H., Essen, Germany Filed Feb. 19, 1957, Ser. No. 641,155

3 Claims. (Cl. 24-20511) Starting pieces of sliding clasp fasteners consist gen- '.erally of a U-shaped piece of sheet metal which is mounted in front of the first fastening elements on the bead of the fastening band and is simply pressed against the head by means of its sides.

It is not possible to employ such starting pieces and to mount them in such manner in the case of spiral wire fasteners having a spiral wire made of metal or plastic material; this is because the end of the spiral wire is free and therefore it is not possible to press such a starting piece simply round the edge of the band before the last winding.

According to the invention, it is on the contrary nec essary with spiral wire fasteners to proceed in such a manner that the last windings of each chain are also grasped by a starting piece and are permanently connected with the band in order to prevent from the start a gradual loosening of the spiral wire. In this connection it is not suflicient to employ a usual starting piece of the previously mentioned type since in that case the attachment of the last spiral wire windings on to the band is insuflicient.

In order to meet these requirements, the invention provides a starting piece of spiral wire fasteners which is characterised in that its fiat form has parallel slide edges, one end being in the shape of a truncated cone and at the other end comprising two tips formed by cutting away a segment corresponding in shape to the truncated cone, said segment being transposed parallel to the truncated part in the longitudinal direction, and characterised in that the truncated cone and the two tips are bent vertically or approximately vertically in relation to the median part of the piece in order to be mounted on the spiral wire end of a fastener chain.

Such a starting piece enables on the one hand a production without waste from a flat wire and has the advantage that it can be placed round the initial windings of the spiral wire and can be rolled up, the median part grasping the windings and the tips piercing through the band or the bead edge of the band and thereby enclosing the truncated cone disposed against the other side of the band. By this means a solid attachment of the beginning of the spiral wire on to the band is attained. By rolling up the starting piece the encompassed spiral wire windings are also compressed in their diameter so that the external circumference of the starting piece corresponds to the external circumference of the spiral wire or is smaller than it. By this means gradual transition edges from the spiral wire to the starting piece are prevented and so the starting pieces are not strained in the slider by jamming.

In order to produce and mount starting pieces according to the invention on to the end of spiral wire zip fastener chains it is advantageous to proceed in such a manner that from a flat wire of the width of the starting piece, a starting piece is each time out off by means of .a cutting punch having a cutting edge corresponding to a truncated cone, and that by means of the cutting punch Raiented July 1 9, 1960 ice the end of the out off starting piece which is provided with the two tips, and by means of a bending punch the truncated cone end resulting from. the prior cutting of a starting piece are bent round a bending tongue disposed symmetrically, said bending tongue serving as a support of the median part of the starting piece, whereupon the bending tongue is retracted to strip off the U-shaped starting piece and the starting piece is pressed against a clinch plate receiving the fastener chain through lowering a clinch punch, whereby the starting piece with the tips and the cone head are rolled round the end of the spiral wire and the tips pierce through the band of the bead of the band.

According to the invention it is, however, possible to produce first the U-shaped starting pieces, to sort them thereafter and finally to roll them round the end of the spiral wire with a special device.

The accompanying drawing shows the starting piece, and the device for producing and for mounting this starting piece, according to the invention:

Fig. 1 shows a plan view of the starting piece, in fiat developed form.

Fig. 2 shows a front view of the starting piece bent to a U-shape.

Fig. 3 shows a side view of the starting piece of Fig. 2.

Fig. 4 shows a rolled up starting piece.

Fig. 5 shows a plan view of a spiral wire fastener chain with the starting piece mounted.

Fig. 6 shows a section along the line VI-VI of Fig. 5.

Fig. 7 shows a schematic side view of the device for producing and mounting the starting pieces on a spiral wire fastener chain.

Fig. 8 shows a section along the line VlII-VIII of Pig. 7.

Fig. 9 shows a view of the bending tongue with a clinch punch and a clinch plate seen in the direction of the arrow IX of Fig. 7.

The starting piece for spiral wire zip fasteners according to the invention is cut out of a flat wire 1 having the width of the starting piece in such a manner that its fiat face according to Fig. 1, has parallel side edges, a truncated cone 2 at one end, and two pointed tips 3 and 4 at the other end. These tips are produced by cutting out a segment corresponding to the truncated cone 2, whereby the edges of the segment lie parallel, in longitudinal direction, to the corresponding edges of the truncated cone. This fiat plate is bent at its central zone 5 to form a U-shaped starting piece as shown in Figs. 2 and 3 and is rolled round the end windings of the spiral wire 6 of a zip fastener chain in such a manner that the end edges of the truncated cone 2 come to bear against one side of the fastening band 7, whilst the central part 5 with the tips 3 and 4 are rolled round the spiral wire windings until the tips 3 and 4 pierce through the band 7 or the bead 7a of the band and thereby partially enclose the truncated cone 2 laterally. Such a rolled up starting piece is shown, somewhat enlarged, in Fig. 4.

In order to produce the starting pieces and in order to mount the starting pieces on to the end windings of a fastener chain it is advantageous to proceed as follows. A flat metal wire having the width of the starting pieces according to Fig. 1 is first led with its free end to a cutting plate 8 and the free end of the flat wire 1 is cut by means of a cutting and bending punch 9, the cutting plate 8 and the cutting punch 9 being correspondingly shaped so that the flat wire end 1 now has a shape 2 of a truncated cone. Now begins the periodical production of the starting pieces, and the flat wire 1 is'periodically advanced each time according to the partial length of the starting piece. When advancing, the fiat wire passes through a slot 10 of a bending tongue 11 and this slot 10 is provided in such a manner that its open side lies in the direction of th e spiral wire 6 as can be seen from Figures 7 and 9. The free end of the flat wire with the cone head 2 projects out of the slot 10 of the bending tongue 11 and the width of the bending tongue corresponds approximately to the width of-the central part of the starting piece. Above the part of the flat wire which projects beyond the bending tongue there is provided a bending punch 12 operating parallel with the cutting and bending punch 9. When the flat wire has taken the prescribed position, the cutting and bending punch 9 and at the same time also the bending punch 12 is lowered, so that by means of the cutting punch 9 a starting piece of the form shown in Fig. 1 is cut from the flat wire 1, whereupon by a further lowering of the punches 9 and 12 the free ends of the starting piece with the cone head 2 and the tips 3 and 4 are vertically bent downwardly round the bending tongue, the bending tongue 11 serving as a support to the central part 5. The starting piece is produced in this manner.

The starting pieces produced in the previously described manner can now be conveyed to a sorting device and from there to a rolling on device by means of which the starting piece will, in the previously mentioned manner be rolled round an initial winding of a spiral wire fastener chain.

However, it is also possible to combine the device for producing the starting pieces with a rolling on device. For this purpose the upper part of the bending punch '11 is so constructed that a free middle part is bounded by two side walls 11a disposed parallel to the spiral wire 6. The surfaces of these side walls 1111 have a slope 11b disposed at the open side of the slot 10. Above this bending tongue is disposed a clinch punch 13 operating vertically which has a plane lower face and lateral segments, whose upper edges comprise sloping faces which correspond to the slope 11b of the bending tongue and operate against these sloping faces 11b. If this clinch punch 13 is lowered after producing the U-shaped starting piece, the bending tongue 11 will be pressed out of the feed zone of the flat wire by means of the sloping faces 11b and the corresponding sloping faces of the clinch punch 13, and at the same time the U-shaped starting piece is stripped off from the bending tongue 11 and is maintained in its position by guides (not shown) until the horizontal lower face of the clinch punch bears against the starting piece 5. Beneath the bending tongue 11 there now lies a clinch plate 14 having a curvature 15 which extends perpendicularly to the longitudinal direction of the flat wire 1. The spiral wire 6 is introduced in this curvature 15, the fastener band 7 lying fiat on the surface of the clinch plate 14. By means of this clinch plate 14 and the fastener chain which is introduced, as the starting piece is further pressed down by means of a further lowering of the clinch punch 13, the cone end 2 comes to bear against the upper side of the fastener band 7 whilst the tips 3 and 4 thrust against the curvature 15 of the clinch plate 14 and then roll up, whereby the central part 5 of the starting piece encompasses the initial windings of the spiral Wire 6 and the tips pierce through the band 7 of the head of the band. Thereby the starting piece assumes essentially a shape as indicated in Figs. 4 to 6. By the rolling up of the starting piece by means of the clinch punch 13 and the clinch plate 14 the initial windings of the spiral wire 6 are compressed and so their diameter is reduced, possibly to such an extent that the outer circumference of the starting piece coincides with the outer circumference of the adjacent spiral windings of the spiral wire 6 or, is smaller than that. By this means there are no edges projecting beyond the circumference of the spiral windings which could jam or catch in the fastener slider and could possibly lead to a loosening of the starting pieces. The initial windings of the spiral wire are solidly and intimately connected with the fastener band 7 by means of this starting piece, so that the end windings can no longer become loosened.

In order to mount the starting pieces on to the initial windings of the individual fastener chains the processes clinch plate 14.

described are repeated periodically. In order to ensure that each time the same number of windings is encompassed at the beginning of the spiral wire by the starting piece, it is advantageous to provide a stop 16 in the curvature 15 of the clinch plate 14 as is indicated in Figs. 6 and 9. This stop is disposed with its stop edge approximately beneath the ground face of the slot 10 of the bending tongue 11 and its height corresponds to the height of the spiral Wire windings which project beyond the thickness of the fastener band 7. In this manner it is possible to place the spiral wire fastener chains always in a uniform position in the curvature 15 of the -It is possible with zip fastener chains with spiral wires made of a plastic material to tye the plastic material at will and to give it the same colour as the fastener band. In order to produce the starting pieces in the same colour it is possible to provide the outer surface of the starting pieces or the upper side of the flat wire strip leading to the described device with a special lacquer having the same colour as the fastener and withstanding the attack from the described bending and rolling up tools.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a separable slide fastener of the type having a pair of parallel tapes with their meeting edges each having a spiral coil carried thereby, and a slider carried by said coils to interlock and open said coils 'by movement in one direction or the other along the length of the tapes, means for clamping the terminal end of each coil to its respective tape, said clamping means comprising a strip having a truncated cone male portion at one end and a female corresponding reentrant portion at the other end, the sides of the strip at the female end forming prongs, said strip being clamped around the coil member with the said male portion engaging the surface of the tape on one side thereof, and with said female portion engaging the tape on the other side thereof, the pronged portions penetrating the tape and spanning the cone portion at the other end of the strip.

2. A device according to claim 1 in which the diameter of the clamping means over the spiral coil is no greater than the mean diameter of the exposed portion of the coil.

3. In a separable slide fastener of the type having a pair of parallel tapes with their meeting edges each having a spiral coil carried thereby and a slider carried by said coils to interlock and open said coils by movement in one direction or the other along the length of the tapes, means for clamping the terminal end of each coil to its respective tape comprising a strip having a trunctated cone male portion at one end and a female corresponding reentrant, cutout portion at the other end, the sides of the strip at said female end forming prongs, said strip being clamped around the coil member with said male portion engaging the surface of the tape on one side thereof, and with said female portion engaging the tape on the other side thereof, the pronged portions penetrating the tape and extending along the side of the cone portion, the male portion extending into the female portion, the strip having an external diameter no greater than the mean diameter of the exposed length of the coil, said strip forming a slider stop member at the end of the coil to limit the movement of the slider.

References Cited in the file of this patent UNITED STATES PATENTS 2,198,345 Legat Apr. 23, 1940 2,296,380 Smith Sept. 29, 1942 2,299,230 Hanseon Oct. 20, 1942 2,483,703 Legat Oct. 4, 1949 2,691,198 Flood Oct. 12, 1954 2,766,631 Van Sittert Oct. 16, 1956 2,832,119 Neitlich Apr. 29, 1958 

